# 9.2 汽车类
class Car():
    """一次模拟汽车的简单尝试"""

    def __init__(self,make,model,year):
        """初始化汽车描述的属性"""
        self.make=make
        self.model=model
        self.year=year

    def get_descriptive_name(self):
        """返回整洁的描述性信息"""
        long_name=str(self.year)+' '+self.make+' '+self.model
        return  long_name.title()

my_new_car=Car('audi','a4','2016')
print(my_new_car.get_descriptive_name())

#加入带默认值得属性，直接修改，防止回调
class Car():
    """一次模拟汽车的简单尝试"""

    def __init__(self,make,model,year):
        """初始化汽车描述的属性"""
        self.make=make
        self.model=model
        self.year=year
        self.odometer_reading=0

    def get_descriptive_name(self):
        """返回整洁的描述性信息"""
        long_name=str(self.year)+' '+self.make+' '+self.model
        return  long_name.title()

    def read_odometer(self):
        print("This car has "+str(self.odometer_reading)+' miles on it.')

    def update_odometer(self,mileage):
        """打印一条指出汽车里程的消息"""
        if mileage>=self.odometer_reading:
            self.odometer_reading=mileage
        else:
            print("You cannot roll back an odometer")


    def increment_odometer(self,miles):
        """将里程表读数增加指定的量"""
        self.odometer_reading+=miles



my_new_car=Car('audi','a4','2016')
print(my_new_car.get_descriptive_name())


my_used_car=Car('subaru','outback',2013)
print(my_used_car.get_descriptive_name())

my_used_car.update_odometer(23500)
my_used_car.read_odometer()

my_used_car.increment_odometer(100)
my_used_car.read_odometer()




